Fire Compartment Upper-Layer Temperature Prediction Considering Excess Fuel Gas

In this study, combustion experiments were conducted by changing the fire source conditions and opening conditions for excess fuel gas using a large-scale fire compartment. It was found that the occurrence of external flames depends on the opening factor A √H , surface area of the wall AT, and heat release rate (HRR) QC inside the fire compartment. Moreover, the larger the value of A √H in the experiment, the greater is the temperature rise in the compartment. McCaffrey's proposed temperature prediction model for the upper layer of the fire compartment was also modified and validated.

Fire Temperature Based on the Time and Resistance of Buildings—Predicting the Adoption of Fire Safety Measures

During a fire in enclosed spaces, having structures with a good level of resistance is very important. The post flashover fire time interval, during which rescue squads operate, is important to verify if the structure can still resist fire for an acceptable time interval. This can be determined through the REI value. Hence, the way the fire develops must be examined together with the trend of the temperature that might guarantee that the structure will resist the heat flux released during the combustion. This article examines and compares, through a case study, the most important methods for analysis of the fire risk: the prescriptive approach and the simplified performance-based approach. The performance-based method (more suitable for the actual planning demand with respect to the more cautious prescriptive approach) is affected by the parameters influencing its development. The goal of this article is to provide a graph (based on parameters like the type of building, opening factor “O” and fire load “q”) that might be used by designers and architects to carry out the planning phase and adopt fire prevention systems before dealing with the assessments required by the engineering field for the fire risk analysis.

Electromagnetic Design of Concentrated Winding in a Direct-Drive Permanent Magnet Wind Generator with Evaporative-Cooling and Inner-Cooling System

This paper describes the fundamental principle of the direct-drive permanent magnet wind generator with evaporative-cooling and inner-cooling system and raises a method to apply concentrated winding to the electromagnetic design of this motor in order to simplify its processing technic. It also includes simulation and comparison of electromotive force of fundamental wave produced by concentrated winding under different slot-opening factors. A reasonable slot-opening factor was selected in the electromagnetic design of a 2 MW direct-drive permanent magnet wind generator with evaporative-cooling and inner-cooling system and the validity of the design has been proved by simulation.

The Study of Rarefied Gas Flow Through Microfilters With Different Openings Using MONIR-DSMC

The main objective of this work is to evaluate the pressure loss at low subsonic rarefied flow through a microfilter having different opening shapes. As is known, a filter with a lower pressure drop is more suitable for different industrial and medical applications. We use our own developed DSMC solver, i.e., 3D MONIR-DSMC code to lunch our study. MONIR uses the NTC (no-time-counter) scheme to model the collision process. The VHS model is also chosen to simulate collision between particle pairs. The Opening factor which is known as one of the most important parameters affecting the microfilter design, is taken constant. The results show that the pressure drop for a rectangular holes is greater than the other hole shapes. Also, the hexagonal hole shapes provide efficient manners compare with circular, rectangular and cubic hole shapes, considering constant opening factor and hydraulic diameter magnitudes.